With longer days and warmer temperatures, we can go ahead with wing and planting. If there is late frost forecast, then cover seedlings with garden fleece. Fruit blossom can be damaged by late frosts and spraying with water early in the morning before the sun is high can save things. One can start pruning fan, cordon and espalier fruit as soon as active growth starts, this keeps down the size of the tree and encourages fruit bud formation. Prune plum & cherry trees now as they are susceptible to silver leaf if their wood is cut later on. Give a high N feed to blackcurrants and blackberries. After forcing rhubarb one should feed with a general fertiliser and leave until next year. Keep a look out for early aphid attack and squash them if a small number or spray if a large infestation. Unless all the aphids are killed, they rapidly multiply until their number is far more than when one started to spray. Big bud (or rather big bud mite) can be a pest on blackcurrants, the flowers look red rather than grey, affected plants should be dug up and burnt. New resistant varieties are ‘Farleigh’, ‘Foxendown and ‘Ben Hope’. All fruit spraying should be done early in the morning when there are less pollinating insects around.
There was recently an interesting programme in the TV Country-wise series on worms. They do a lot of soil cultivation for us and should be encouraged by increasing the amount of organic matter in our soils. These creatures have five hearts and are hermaphrodites -strange ! .As the soil dries out in summer months, worms drag leaves and other organic material down into the earth thus aerating and watering lower depths.
Main crop potatoes should be planted in the second half of May and earlies earthed up. Sow beetroot, carrots, cauliflower, kohl rabi, lettuce, leeks, radish, turnips, spring onions, peas and perpetual spinach, all in well prepared soil. Tomatoes, cucumbers and salads can all be sown in a frost free greenhouse. Tomatoes started in small pots should be put in larger pots or in grow-bags (outside if hardened off). Damping off of seedlings can be a problem. Plenty of ventilation in the greenhouse can help as also can Cheshunt Compound for washing pots and seed trays.
Divide clumps of herbaceous perennials that you want to propagate those that have grown too large for their space and those that are flowering poorly or do not like the position one has chosen for them.
Hardy annuals can be grown in pots to provide colour where needed in the garden. Hanging baskets can be put up towards mid May.
ADAM